Process for the continuous conversion of ferruginous materials into spongy metallic agglomerates



. g- 1933- A. FOLLIET ETAL 1,924,034 PROCESS FOR THE CONTINUOUS CONVERSION OF FERRUGINOUS MATERIALS INTO SPONGY METALLIC AGGLOMERATES Filed Aug. 10, 1952 FUEL,

RsAc lo -1[. ZONE PREHEATING ZONE HIGH IEMPERATURE.

f] 5/5215 al nblen ohin /-ven/T af$$ parenteral Aug. 22, recs raocass Fore mature THE GEDNTENE3 CNV3ElR-' SEIQDN (37F FERREJGENKDUS TM EERKALS SPQNGY METALLHG AG:

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GLQIVL ERA'EIES Alexandre Folliet and Nicolas Sainderichin, Paris, France Application August re, 1932,

and in France August iii, 193i. 2 @laims. (i. hi t-i) is subjected to the penetrating jets of air, raised In French Patents Nos. 684,174 and 697,006 has been set forth the action of the air, previously raised to high temperatures acting upon a rnix= ture of ores and reducing carbon, advancing progressively in a refractory enclosure. The penetrating insufliation, by the jets of a special twyer, taking place in the final reaction zone, in proximity to the discharge, occasion by the calorific energy developed the continuous agglomeration of the residues, in which the iron is found in the form of magnetic oxide and a little inthe state of metal.

This formation of magnetic oxide (F6304) ,as experience has shown, occurs progressively during the travel .of the material until its arrival at the final zone of insufiation of air at high temperatures.

In pursuing these applications by utilizing air raised to from 750 to 850 0., with suitable dis charge volume and pressure, with a suitable combustible previously added, it has been possible to carry on, practically and with continuous operation, the manufacture of spongy metallic agglomerates, veritable iron sponge which is directly utilizable for the manufacture of steel.

This iron sponge is moreover of remarkable softness.

This practical operation forms the subject of the present patent.

The raw material,-in a suitable state of division, either in the state of fines, like blast-furnace dust, or, for ores and ferruginous materials, crushed from to 8 millimetres; this material should be very uniformly moistened, according to its nature, with a proportion of 5 to per cent. of water.

Zlhe material thus moistened is supplemented by a variable percentage of small oven coke orlean anthracite coals, etc., of a screening of 0 to 8 millimetres. According to the iron content the proportion may vary from 10 to per cent. in relation to the fixed carbon contained. The mixture should beintimate. j By its progressive travelling in the oven the' mixture is subjected to progressive dessication and progressive heating, likewise in approaching the reaction zon as the conversion of F6203 into F9304 progresses to, a maximum; The mixture, arriving thus at a dull red heat in the reaction zone, under a reduced thickness,

to from 750'to 850 The special twyer.

Serial No. 628,544.

0., blownin throughthe fixed'carbon of the mixture is burnt, in the mass, in the form of CO, with a considerable evolution nascent carbon reacts instantaneously the formation of pasty metallic ity of this iron sponge arises ate escape, at this prevailing of calorific energy. This monoxide at high temperatures upon the F8304, causing iron. The porosfrom the immeditemperature resulting from the calorific energy evolved, of the gaseous carbonic acid resulting from the reaction:

Fe3ol+ico (nascent) sre-i-ecoz An example of for carrying out shown in the accompanying a suitable form of apparatu the process described above is diagrammatic drawa longitudinal section of the s-s'ection on the line H-II of Figure 3 a cross-section on the line ill-III of Figure 1.

the final zone. such treatment e The preheated products after nter a cylindrical chamber of 5,

increased cross-section where they receive the necessary excess piping and hopper R. k

of reducing carbon from the The 'intimatemixture of the products of the preheating and carbon then pass under jets t,

of air at a high. temperature from the main twyer T.

are led back along the chamber F, products of combustion into a passing through tionary and backward lead efiecting Any metals volatilized by this reaction together with chamber D, after a flared pipe E, which is statraversed by the feed pipe C, this preliminary heating of the layer of material moving forward.

,The resulting spongy iron in the form of substantially spherical lumps is automatically discharged into a chamber S.

Having now described our claim as new anddesire to secure Patent is:-

' 1'. A continuous invention what we process for reducing iron oxide by Letters in i'erruginous material to metallic iron in spongy form which consists in moistening said material, feeding forward said moistened "material in a thin layer, mixing carbonaceous fuel with said material prior to said layer entering the final zone of its forward feed, and subjecting said mixture to the action of penetrating blasts of air heated to temperatures of the order of 750 to 800 C., the gases formed within the mixture due to the action of said penetrating blasts serving as they escape therefrom to give a spo y form to the metallic iron produced by the reaction, said car- 

